Indicia reading apparatus having sequential row exposure termination times

ABSTRACT

There is set forth herein an indicia reading apparatus having an image sensor array including a plurality of pixels arranged in a plurality of rows and columns of pixels. The image sensor array can include a frame exposure period in which a certain subsequent and further subsequent row exposure periods have common exposure initiation times and sequential exposure termination times. An indicia reading apparatus can be controlled so that a light source bank of an illumination pattern assembly for projecting an illumination pattern is energized during an illumination period that overlaps a frame exposure period. The apparatus can be further controlled so that an illumination period terminates at or prior to an exposure termination time of the certain row.

FIELD OF THE INVENTION

The present invention relates in general to optical based registers, andparticularly is related to an image sensor based indicia readingapparatus.

BACKGROUND OF THE INVENTION

Indicia reading apparatus for reading decodable indicia are available inmultiple varieties. For example, minimally featured indicia readingapparatus devoid of a keyboard and display are common in point of saleapplications. Indicia reading apparatus devoid of a keyboard and displayare available in the recognizable gun style form factor having a handleand trigger button (trigger) that can be actuated by an index finger.Indicia reading apparatus having keyboards and displays are alsoavailable. Keyboards and display equipped indicia reading apparatus arecommonly used in shipping and warehouse applications, and are availablein form factors incorporating a display and keyboard. In a keyboard anddisplay equipped indicia reading apparatus, a trigger button foractuating the output of decoded messages is typically provided in suchlocations as to enable actuation by a thumb of an operator. Indiciareading apparatus in a form devoid of a keyboard and display or in akeyboard and display equipped form are commonly used in a variety ofdata collection applications including point of sale applications,shipping applications, warehousing applications, security check pointapplications, and patient care applications.

Some indicia reading apparatus are adapted to read bar code symbolsincluding one or more of one dimensional (1D) bar codes, stacked 1D barcodes, and two dimensional (2D) bar codes. Other indicia readingapparatus are adapted to read OCR characters while still other indiciareading apparatus are equipped to read both bar code symbols and OCRcharacters.

SUMMARY OF THE INVENTION

There is set forth herein an indicia reading apparatus having an imagesensor array including a plurality of pixels arranged in a plurality ofrows and columns of pixels. The image sensor array can include a frameexposure period in which a certain subsequent and further subsequent rowexposure periods have common exposure initiation times and sequentialexposure termination times. An indicia reading apparatus can becontrolled so that a light source bank of an illumination patternassembly for projecting an illumination pattern is energized during anillumination period that overlaps a frame exposure period. The apparatuscan be further controlled so that an illumination period terminates ator prior to an exposure termination time of the certain row.

BRIEF DESCRIPTION OF THE DRAWINGS

The features described herein can be better understood with reference tothe drawings described below. The drawings are not necessarily to scale,emphasis instead generally being placed upon illustrating the principlesof the invention. In the drawings, like numerals are used to indicatelike parts throughout the various views.

FIG. 1 is a block design illustrating an exemplary imaging apparatus.

FIG. 2 is a physical form view illustrating an exemplary imagingapparatus.

FIG. 3 is a timing diagram illustrating operation of an exemplaryimaging apparatus.

FIG. 4 is a timing diagram illustrating operation of an exemplaryimaging apparatus.

DETAILED DESCRIPTION OF THE INVENTION

There is set forth herein an indicia reading apparatus 1000 having animage sensor array including a plurality of pixels arranged in aplurality of rows and columns of pixels. The image sensor array caninclude a frame exposure period in which a certain subsequent andfurther subsequent row exposure periods have common exposure initiationtimes and sequential exposure termination times. An indicia readingapparatus can be controlled so that a light source bank of anillumination assembly for projecting an illumination pattern isenergized during an illumination period that overlaps a frame exposureperiod. The apparatus can be further controlled so that an illuminationperiod terminates at or prior to an exposure termination time of thecertain row.

Configured or described, the apparatus allows for use of a low cost highresolution image sensor integrated circuit and operative withsignificantly increased motion tolerance, resulting in improved imagequality of captured frames of image data substantially free of motionblur.

An exemplary hardware platform for support of operations describedherein with reference to an image sensor based indicia reading apparatusis shown and described with reference to FIG. 1.

Indicia reading apparatus 1000 can include an image sensor 1032comprising a multiple pixel image sensor array 1033 having pixelsarranged in rows and columns of pixels, associated column circuitry 1034and row circuitry 1035. Associated with the image sensor 1032, can beamplifier circuitry 1036 and an analog to digital converter 1037. Analogto digital converter 1037 converts image information in the form ofanalog signals read out of image sensor array 1033 into imageinformation in the form of digital signals. Image sensor 1032 can alsohave an associated timing and control circuit 1038 for use incontrolling, for e.g., the exposure period of image sensor 1032, gainapplied to the amplifier 1036. The noted circuit components 1032, 1036,1037, and 1038 can be packaged into a common image sensor integratedcircuit 1040. In one example, image sensor integrated circuit 1040 canbe provided by an Aptina MT9P031 image sensor integrated circuitavailable from Aptina Imaging Corporation of San Jose, Calif. The notedimage sensor integrated circuit from Aptina includes a global resetrelease function which when activated results in an exposure period fora plurality of rows being initiated at a common time with the exposureperiod termination times for the plurality of rows being sequential.Image sensor integrated circuit 1040 can incorporate a Bayer patternfilter. In such an embodiment, CPU 1060 prior to subjecting a frame tofurther processing can interpolate pixel values intermediate of acertain channel of pixel values, (e.g., red, green, or blue) pixelvalues at pixel positions of the single channel (e.g., red, green, blue)for development of a monochrome frame of image data.

In the course of operation of apparatus 1000, image signals can be readout of image sensor 1032, converted and stored into a system memory suchas RAM 1080. A memory 1085 of apparatus 1000 can include RAM 1080, anonvolatile memory such as EPROM 1082 and a storage memory device 1084such as may be provided by a flash memory or a hard drive memory. In oneembodiment, apparatus 1000 can include CPU 1060 which can be adapted toread out image data stored in memory 1080 and subject such image data tovarious image processing algorithms. Apparatus 1000 can include a directmemory access (DMA) unit 1070 for routing image information read outfrom image sensor 1032 that has been subject to conversion to RAM 1080.In another embodiment, apparatus 1000 can employ a system bus providingfor bus arbitration mechanism (e.g., a PCI bus) thus eliminating theneed for a central DMA controller. A skilled artisan would appreciatethat other embodiments of the system bus architecture and/or directmemory access components providing for efficient data transfer betweenthe image sensor 1032 and RAM 1080 are within the scope and the spiritof the invention.

Referring to further aspects of apparatus 1000, lens assembly 200 can beadapted for focusing an image of a decodable indicia 15 located within afield of view 1240 on a substrate 1250 onto image sensor array 1033.Imaging light rays can be transmitted about imaging axis 25. Lensassembly 200 can be adapted to be capable of multiple focal lengths andmultiple best focus distances. A combination of image sensor array 1033and imaging lens assembly 200 can be regarded as an imaging assembly1100.

Apparatus 1000 can also include an illumination pattern light sourcebank 1204 and associated light shaping optics 1205 for generating anillumination pattern 1260 substantially corresponding to a field of view1240 of apparatus 1000. The combination of bank 1204 and optics 1205 canbe regarded as an illumination assembly 1206 for projection of anillumination pattern 1260. Light source bank 1204 can be energized forprojection of illumination pattern 1260. Apparatus 1000 can also includean aiming pattern light source bank 1208 and associated light shapingoptics 1209 for generating an aiming pattern 1270 on substrate 1250. Thecombination of bank 1208 and optics 1209 can be regarded as an aimingassembly 1210 for projection of an aiming pattern 1270. In use,apparatus 1000 can be oriented by an operator with respect to asubstrate 1250 bearing decodable indicia 15 in such manner that aimingpattern 1270 is projected on a decodable indicia 15. In the example ofFIG. 1, decodable indicia 15 is provided by a 1D bar code symbol.Decodable indicia 15 could also be provided by a 2D bar code symbol oroptical character recognition (OCR) characters. Each of illuminationpattern light source bank 1204 and aiming pattern light source bank 1208can include one or more light sources. In one embodiment, apparatus 1000can be adapted so that illumination assembly 1206 can project light in anarrow wavelength band, e.g., a set of wavelengths in the red band (orgreen band, or blue band), and further so that apparatus 1000 includes awavelength selective optical filter 2110 that filters light outside ofthe narrow wavelength band. Optical filter 2110 can be disposed in theoptical receive path about above imaging axis 25.

Lens assembly 200 can be controlled with use of electrical power inputunit 55 which provides energy for changing a plane of optimal focus oflens assembly 200. In one embodiment, an electrical power input unit 55can operate as a controlled voltage source, and in another embodiment,as a controlled current source. Illumination pattern light source bank1204 can be controlled with use of illumination pattern light sourcecontrol circuit 1220. Aiming pattern light source bank 1208 can becontrolled with use of aiming pattern light source bank control circuit1222. Illumination pattern light source bank 1204 can comprise one ormore light source. Aiming pattern light source bank 1208 can compriseone or more light source. The one or more light source of light sourcebank 1204 and/or light source bank 1208 can be provided by, e.g., one ormore light emitting diode, LED.

Electrical power input unit 55 can apply signals for changing opticalcharacteristics of lens assembly 200, e.g., for changing a focal lengthand/or a best focus distance of (a plane of optimum focus of) lensassembly 200. Illumination pattern light source bank control circuit1220 can send signals to illumination pattern light source bank 1204,e.g., for changing a level of illumination output by illuminationpattern light source bank 1204. Aiming pattern light source bank controlcircuit 1222 can send signals to aiming pattern light source bank 1208,e.g., for changing a level of illumination output by aiming patternlight source bank 1208.

Apparatus 1000 can also include a number of peripheral devices includingtrigger 1120 which may be used to make active a trigger signal foractivating frame readout and/or certain decoding processes. Apparatus1000 can be adapted so that activation of trigger 1120 activates atrigger signal and initiates a decode attempt. Specifically, apparatus1000 can be operative so that in response to activation of a triggersignal, a succession of frames can be read out and captured by way ofread out of image signals from image sensor array 1033 (typically in theform of analog image signals) and then storage of image signals (in theform of digital image signals) after conversion into memory 1080 (whichcan buffer one or more of the succession of frames at a given time).

CPU 1060 can be operative to subject one or more of the succession offrames to a decode attempt. For attempting to decode a bar code symbol,CPU 1060 can process image data of a frame corresponding to a line ofpixel positions (e.g., a row, a column, or a diagonal set of pixelpositions) to determine a spatial pattern of dark and light cells andcan convert each light and dark cell pattern determined into a characteror character string via table lookup.

Apparatus 1000 can include various interface circuits for couplingvarious of the peripheral devices to system address/data bus (systembus) 1500, for communication with CPU 1060 also coupled to system bus1500. Apparatus 1000 can include interface circuit 1028 for couplingimage sensor timing and control circuit 1038 to system bus 1500,interface circuit 1118 for coupling electrical power input unit 55 tosystem bus 1500, interface circuit 1218 for coupling illumination lightsource bank control circuit 1220 to system bus 1500, interface circuit1224 for coupling aiming light source bank control circuit 1222 tosystem bus 1500, and interface circuit 1119 for coupling trigger 1120 tosystem bus 1500. Apparatus 1000 can also include a display 1122 coupledto system bus 1500 and in communication with CPU 1060, via interface1121, as well as pointer mechanism 1124 in communication with CPU 1060via interface 1123 connected to system bus 1500. Apparatus 1000 can alsoinclude keyboard 1126 in communication with CPU 1060 via interface 1125connected to system bus 1500. Apparatus 1000 can also include rangedetector 1128 in communication with CPU 1060 via interface 1127connected to system bus 1500. Range detector 1128 can be e.g., anultrasonic range detector. Apparatus 1000 can also include acommunication interface 1050 coupled to system bus 1500 and incommunication with CPU 1060. Interface 1050 can be e.g., an Ethernet USBor IEEE 802.11 interface. Apparatus 1000 can be in TCP/IP communicationwith one or more external processor equipped apparatus.

Apparatus 1000 can capture frames of image data at a rate known as aframe rate. A typical frame rate is 60 frames per second (FPS) whichtranslates to a frame time (frame period) of 16.6 ms. Another typicalframe rate is 30 frames per second (FPS) which translates to a frametime (frame period) of 33.3 ms per frame.

A physical form view of apparatus 1000 in one embodiment is shown inFIG. 2. Trigger 1120, display 1122, pointer mechanism 1124, and keyboard1126 can be disposed on a common side of a hand held housing 1014 asshown in FIG. 2. Display 1122 and trigger 1120 and pointer mechanism1124 in combination can be regarded as a user interface of apparatus1000. Display 1122 in one embodiment can incorporate a touch panel fornavigation and virtual actuator selection a virtual trigger display inwhich case a user interface of apparatus 1000 can be provided by display1122. A user interface of apparatus 1000 can also be provided byconfiguring apparatus 1000 to be operative to be reprogrammed bydecoding of programming bar code symbols. A hand held housing 1014 forapparatus 1000 can in another embodiment be devoid of a display and canbe in a gun style form factor. Imaging assembly 1100, illuminationassembly 1206 and aiming assembly 1210 can be disposed in hand heldhousing 1014.

In one embodiment, there are a succession of frames exposed, read out,stored into memory 1080 and subject to processing by CPU 1060 during atime that trigger signal 5504 is active. The processing of each framecan include a decode attempt as described herein. As explained, atrigger signal 5504 can be made active by depression of trigger 1120 andcan be de-activated by release of trigger 1120 or a successful decode orexpiration of a timeout. A timing diagram illustrating operation ofimaging apparatus 1000 is shown in FIG. 3.

Referring to the timing diagram of FIG. 3, signal 5504 is a triggersignal which can be made active by actuation of trigger 1120, and whichcan be deactivated by releasing of trigger 1120. A trigger signal mayalso become inactive after a time out period or after a successfuldecode of a decodable indicia. Signal 5510 is a frame exposure signal.Logic high periods of signal 5510 define frame exposure periods 5320,5322, 5324. Signal 5512 is a read out signal. Logic high periods ofsignal 5512 define read out periods 5420, 5422, and 5424. Processingperiods 5520, 5522, and 5524 can represent processing periods duringwhich time CPU 1060 of apparatus 1000 processes stored (e.g., buffered)frames representing a substrate that can bear decodable indicia. Suchprocessing can include processing for attempting to decode a decodableindicia as described herein.

With further reference to the timing diagram of FIG. 3, an operator attime, t₀, can activate trigger signal 5504 (e.g., by depression oftrigger 1120). In response to trigger signal 5504 being activated,apparatus 1000 can expose a succession of frames. During each frameexposure period 5320, 5322, 5324, 5326 a frame of image data can beexposed.

Referring further to the timing diagram of FIG. 3, signal 5508 is alight pattern control signal. Logic high periods of signal 5508, namelyperiods 5220, 5222, 5224, 5226 define “on” periods for projectedillumination pattern 1260. A light source bank 1204 of illuminationassembly 1206 can be energized to project illumination pattern 1260during illumination periods 5220, 5222, 5224 that overlap frame exposureperiods 5320, 5322, 5324 so that at least a portion of an illuminationperiod occurs during an associated frame exposure period and furtherthat a portion of a frame exposure period occurs during an associatedillumination period. Regarding illumination period 5220, illuminationperiod 5220 commences at a time in common with commencement of frameexposure period 5320 and terminates at or prior to a termination time ofa row exposure period for a certain row of pixels (certain row) of array1033. The certain row of pixels can be a first row of pixels of array1033. The certain row of pixels can be a first row of pixels of array1033 subject to readout. Regarding illumination period 5222,illumination period 5222 commences prior to frame exposure period 5322and terminates at or prior to a time of termination of a row exposureperiod of a certain row of array 1033. Regarding illumination period5224, illumination period 5224 commences after an exposure commencementtime of frame exposure period 5324 and terminates at a time at or priorto a termination time of a row exposure period for a certain row ofarray 1033. At time t₁, trigger signal 5504 can be deactivated e.g.,responsively to a successful decode, a timeout condition beingsatisfied, or a release of trigger 1120. Regarding illumination periods5220, 5222, 5224, the illustrated on times in one embodiment can be“continuously on” on times. The illustrated on times in anotherembodiment can be strobed on times wherein light source bank 1204 isturned on and off rapidly during an illumination period. Light sourcebank 1204 for a duration of an illumination period, e.g., period 5220,5222, 5224 can be energized on and off at a strobing rate. In oneembodiment, a strobing rate can be established so that there are two ormore cycles per illumination period, which in one embodiment is lessthan or equal to 10.0 Hz. In another embodiment less than or equal to8.0 Hz. In another embodiment less than or equal to 5.0 Hz. In anotherembodiment less than or equal to 4.0 Hz. In another embodiment less thanor equal to 3.0 Hz. In another embodiment less than or equal to 2.0 Hz.In another embodiment less than or equal to 1.0 Hz. In anotherembodiment less than or equal to 0.5 Hz. In another embodiment less thanor equal to 0.10 Hz. In one example a strobing rate is greater than 1.0Hz e.g., 2.0 Hz. In one example a strobing rate is between 2.0 Hz and4.0 KHz, e.g., 30.0 Hz. In one example a strobing rate is greater thanor equal to 4.0 KHz, e.g., 4.0 Hz to 1000 KHz or more, e.g., to 10 MHzor more. In one specific embodiment, the strobing rate is between 20 KHzand 40 KHz. In one embodiment the strobing rate is 30 KHz.

Further description of a frame exposure period is set forth withreference to the timing diagram of FIG. 4. The frame exposure periodlabeled with three reference numerals 5320, 5322, 5324 indicated in FIG.4 can be in accordance with any one of frame exposure periods 5320,5322, 5324 and can have an associated illumination period as describedin connection with any of frame exposure period 5220, 5222, 5224 asreferenced in the timing diagram of FIG. 3. Exposure of each row ofimage sensor array 1033 can commence at a common initiation time E, andeach row of image sensor array 1033 can have a different exposuretermination time. In the example as shown in FIG. 4 each row of imagesensor array 1033 can have an exposure termination time that issequential to the exposure termination time of the preceding row. Forexample, row 1 of array 1033 can have an exposure termination time attime Et_(i), row 2 can have and exposure termination time at time Et₂after time Et_(i) and row 3 of array 1033 can have an exposuretermination time at time Et_(a) after time Et₂. In the timing diagram ofFIG. 4 timelines labeled Row 1, Row 2, and Row 3 illustrate row exposureperiods for the first three rows of an M column and N row (M×N) imagesensor array, timelines labeled Row J, Row J+1, Row J+2 illustrate rowexposure periods for middle rows Row J, Row J+1, Row J+2 of image sensorarray 1033 and timelines labeled Row N−2, Row N−1, and Row N illustraterow exposure periods for the last three rows, Row N−2, Row N−1, Row N ofimage sensor array 1033, having an M+N array of pixels.

In connection with FIG. 3 it was described that an illumination periodstart time can be before (period 5222) at (period 5220) or after (period5224) a frame exposure start time. In connection with the timing diagramof FIG. 3 in reference to signal 5508 it was described that atermination time of illumination period e.g., illumination period 5220,5222, 5224 can be at various times within a frame exposure period e.g.,period 5220, 5222, 5224. In connection with the timing diagram of FIG.4, there is shown signal 5508 having on and off (energization andde-energization times) that define an illumination period. Theillumination period is shown as having a certain start time andtermination time (solid lines). However, it is described that the starttime and termination time can be varied as indicated by the dashed linesshown in association with signal 5508. Regarding exemplary illuminationperiod termination time I₁, illumination period termination time I₁illustrates that an illumination period can terminate prior to a timethat a row exposure period for first row, Row 1 ends. Regardingexemplary illumination period termination time I₂, illumination periodtermination time I₂ illustrates that an illumination period canterminate at a time in common with a time that a row exposure period forrow 1. Regarding exemplary illumination period termination time I₃,illumination period termination time I₃ illustrates that an illuminationperiod can terminate at time after time I₂. It can be useful to controlapparatus 1000 so that an illuminaton period terminates at time I₃ wherea first row of image sensor array 1033 subject to readout is not Row 1,but a row of array 1033 after Row 1. For example, if a frame subject toreadout is a windowed frame and a first row of image sensor array 1033subject to readout is Row J it can be useful to terminate illuminationperiod at time I₃, a time at or before an exposure period terminationtime for Row J. Regarding exemplary illumination start time I_(A),exemplary illumination start time I_(A) indicates that an illuminationperiod can commence subsequent to a commencement of a frame exposureperiod. Regarding exemplary illumination start time I_(B), exemplaryillumination start time I_(B) indicates that an illumination period cancommence at a time in common with a frame exposure commencement time.Regarding exemplary illumination start time I_(C), exemplaryillumination start time I_(c) illustrates that an illumination periodcan commence prior to commencement of a frame exposure period.

By controlling an illumination period so that an illumination periodterminates at or prior to an exposure period termination time for afirst row of image sensor array 1033 subject to readout of a framehaving image data representing light incident on array 1033 during aframe exposure period, a quality of a captured frame of image data canbe improved. For example, image blurring problems caused by movementbetween an apparatus 1000 and a target 1250 during frame exposure can bereduced to improve a motion tolerance of apparatus 1000.

A quality of a captured frame can be improved further by adaptingapparatus 1000 to filter out light of a certain wavelength band. In oneembodiment, as set forth in connection with FIG. 1, apparatus 1000 canbe adapted so that illumination assembly 1206 projects light formingillumination pattern 1260 in a certain narrow wavelength band andfurther so that apparatus 1000 includes an optical filter 210 in areceive optical path that filters light outside of the certain narrowwavelength band. In such manner, an amount of light incident on imagesensor array 1033 originating external to illumination assembly 1206(i.e., ambient light) is reduced resulting in a reduction of motion blurartifacts attributed to sequential exposure period termination times.

For further reduction of a ratio of ambient light to light emitted byillumination assembly 1206, and further reduction of motion artifacts,an amplitude of light emitted by illumination assembly 1206 can beincreased. In one embodiment, illumination light source bank controlcircuit 1220 is a “flash” circuit configured to overdrive the one ormore light source of bank 1204 above their maximum continuous operationrating. Illumination light source bank control circuit 1220 can includea boost capacitor that stores energy for quick discharge to energize theone or more light source of light source bank 1204. In one embodiment,the light source(s) of light source bank 1204 can be overdriven to 200%or more of their maximum continuous current rating; in anotherembodiment, 300% or more; in another embodiment 400% or more; in anotherembodiment 1000% or more. In one embodiment, light source bank 1204comprises one or more LED.

For further reduction of a ratio of ambient light to light emitted byillumination assembly 1206, and corresponding reduction of motionartifacts imaging lens assembly 2000 can be provided to include an F# ofgreater than a certain value. In one embodiment, the F# is greater thanor equal to 5.0. In one embodiment, the F# is greater than or equal to6.0. In one embodiment the F# is greater than or equal to 7.0. In oneembodiment, the F# is greater than or equal to 8.0. In one embodiment,the F# is greater than or equal to 9.0. In one embodiment, the F# isgreater than or equal to 10.0. In one embodiment, the F# is greater thanor equal to 15.0. In one embodiment, the F# is greater than or equal to20.0.

A small sample of systems, methods and apparatus that are describedherein is as follows:

A1. An imaging apparatus comprising:

an imaging assembly having an image sensor array and a lens assembly forfocusing an image onto the image sensor array, the image sensor arraycomprising a plurality of pixels arranged in a plurality of rows andcolumns and pixels, the imaging assembly defining a field of view;

an illumination assembly for projecting an illumination pattern duringan illumination period, wherein at least a portion of the illuminationpattern is projected in an area within the field of view;

wherein pixels of the image sensor array are exposed during a frameexposure period in which a certain subsequent and further subsequent rowof pixels of the image sensor array have common row exposure initiationtimes and respectively sequential exposure termination times;

wherein the imaging apparatus is operative to process for attempting todecode decodable indicia image data representative of light incident onthe image sensor array during the frame exposure period;

wherein the illumination period and the frame exposure period arecoordinated so that at least a portion of the illumination period occursduring the frame exposure period and further so that the illuminationperiod ends at a time in common with or earlier than an exposuretermination time of the certain row.

A2. The imaging apparatus of claim A1, wherein light forming theillumination pattern is light within a certain narrow wavelength bandand wherein the apparatus includes a wavelength selective filterfiltering light outside of the certain narrow wavelength band.A3. The imaging apparatus of claim A1, wherein light forming theillumination pattern is light within a certain narrow wavelength bandand wherein the apparatus includes a wavelength selective filterfiltering light outside of the certain narrow wavelength band, andwherein the lens assembly includes an F# greater than or equal to 5.0.A4. The imaging apparatus of claim A1, wherein the certain row is thefirst row of the image sensor array.A5. The imaging apparatus of claim A1, wherein the certain row is afirst row of the image sensor array subject to readout for capture of aframe of image data representing light incident on the image sensorarray during the frame exposure period.A6. The imaging apparatus of claim A1, wherein the certain row and thesubsequent row are successive rows.A7. The imaging apparatus of claim A1, wherein the imaging apparatusincludes a hand held housing in which the image sensor array isdisposed.A8. The imaging apparatus of claim A6, wherein the certain row is thefirst row of the image sensor array subject to readout of a frame ofimage data representing light incident on the image sensor array duringthe frame exposure period.A9. The imaging apparatus of claim A7, wherein the illumination periodand the frame exposure period are coordinated so that the illuminationperiod ends at a time in common with the exposure termination time ofthe certain row.A10. The imaging apparatus of claim A7, wherein the illumination periodand the frame exposure period are coordinated so that the illuminationperiod ends at a time earlier than an exposure termination time of thecertain row.A11. The imaging apparatus of claim A1, wherein the illumination periodand the frame exposure period are coordinated so that the illuminationperiod ends at a time in common with the exposure termination time ofthe certain row.A12. The imaging apparatus of claim A1, wherein the illumination periodand the frame exposure period are coordinated so that the illuminationperiod ends at a time earlier than an exposure termination time of thecertain row.A13. The imaging apparatus of claim A1, wherein the illumination periodcommences prior to the common exposure initiation time of the certainsubsequent and further subsequent rows of the image sensor array.A14. The imaging apparatus of claim A1, wherein the illumination periodcommences at a time in common with the common exposure initiation timeof the certain subsequent and further subsequent rows of the imagesensor array.A15. The imaging apparatus of claim A1, wherein the illumination periodcommences subsequent to the common exposure initiation time of thecertain subsequent and further subsequent rows of the image sensorarray.A16. The imaging apparatus of claim A1, wherein the illuminationassembly is controlled to strobe light forming the illumination patternduring the illumination period.A17. The imaging apparatus of claim A1, wherein the lens assemblyincludes an F# greater than or equal to 5.0.A18. The imaging apparatus of claim A1, wherein the lens assemblyincludes an F# greater than or equal to 9.0.A19. The imaging apparatus of claim A1, wherein the apparatus overdrivesa light source of the illumination assembly during the illuminationperiod.A20. The imaging apparatus of claim A3, wherein the apparatus overdrivesa light source of the illumination assembly during the illuminationperiod.

While the present invention has been described with reference to anumber of specific embodiments, it will be understood that the truespirit and scope of the invention should be determined only with respectto claims that can be supported by the present specification. Further,while in numerous cases herein wherein systems and apparatuses andmethods are described as having a certain number of elements it will beunderstood that such systems, apparatuses and methods can be practicedwith fewer than or greater than the mentioned certain number ofelements. Also, while a number of particular embodiments have beendescribed, it will be understood that features and aspects that havebeen described with reference to each particular embodiment can be usedwith each remaining particularly described embodiment.

We claim:
 1. An imaging apparatus comprising: an imaging assembly havingan image sensor array and a lens assembly for focusing an image onto theimage sensor array, the image sensor array comprising a plurality ofpixels arranged in a plurality of rows and columns and pixels, theimaging assembly defining a field of view; an illumination assembly forprojecting an illumination pattern during an illumination period,wherein at least a portion of the illumination pattern is projected inan area within the field of view; wherein pixels of the image sensorarray are exposed during a frame exposure period in which a certainsubsequent and further subsequent row of pixels of the image sensorarray have common row exposure initiation times and respectivelysequential exposure termination times; wherein the imaging apparatus isoperative to process for attempting to decode decodable indicia imagedata representative of light incident on the image sensor array duringthe frame exposure period; wherein the illumination period and the frameexposure period are coordinated so that at least a portion of theillumination period occurs during the frame exposure period and furtherso that the illumination period ends at a time in common with or earlierthan an exposure termination time of the certain row.
 2. The imagingapparatus of claim 1, wherein light forming the illumination pattern islight within a certain narrow wavelength band and wherein the apparatusincludes a wavelength selective filter filtering light outside of thecertain narrow wavelength band.
 3. The imaging apparatus of claim 1,wherein light forming the illumination pattern is light within a certainnarrow wavelength band and wherein the apparatus includes a wavelengthselective filter filtering light outside of the certain narrowwavelength band, and wherein the lens assembly includes an F# greaterthan or equal to 5.0.
 4. The imaging apparatus of claim 1, wherein thecertain row is the first row of the image sensor array.
 5. The imagingapparatus of claim 1, wherein the certain row is a first row of theimage sensor array subject to readout for capture of a frame of imagedata representing light incident on the image sensor array during theframe exposure period.
 6. The imaging apparatus of claim 1, wherein thecertain row and the subsequent row are successive rows.
 7. The imagingapparatus of claim 1, wherein the imaging apparatus includes a hand heldhousing in which the image sensor array is disposed.
 8. The imagingapparatus of claim 6, wherein the certain row is the first row of theimage sensor array subject to readout of a frame of image datarepresenting light incident on the image sensor array during the frameexposure period.
 9. The imaging apparatus of claim 7, wherein theillumination period and the frame exposure period are coordinated sothat the illumination period ends at a time in common with the exposuretermination time of the certain row.
 10. The imaging apparatus of claim7, wherein the illumination period and the frame exposure period arecoordinated so that the illumination period ends at a time earlier thanan exposure termination time of the certain row.
 11. The imagingapparatus of claim 1, wherein the illumination period and the frameexposure period are coordinated so that the illumination period ends ata time in common with the exposure termination time of the certain row.12. The imaging apparatus of claim 1, wherein the illumination periodand the frame exposure period are coordinated so that the illuminationperiod ends at a time earlier than an exposure termination time of thecertain row.
 13. The imaging apparatus of claim 1, wherein theillumination period commences prior to the common exposure initiationtime of the certain subsequent and further subsequent rows of the imagesensor array.
 14. The imaging apparatus of claim 1, wherein theillumination period commences at a time in common with the commonexposure initiation time of the certain subsequent and furthersubsequent rows of the image sensor array.
 15. The imaging apparatus ofclaim 1, wherein the illumination period commences subsequent to thecommon exposure initiation time of the certain subsequent and furthersubsequent rows of the image sensor array.
 16. The imaging apparatus ofclaim 1, wherein the illumination assembly is controlled to strobe lightforming the illumination pattern during the illumination period.
 17. Theimaging apparatus of claim 1, wherein the lens assembly includes an F#greater than or equal to 5.0.
 18. The imaging apparatus of claim 1,wherein the lens assembly includes an F# greater than or equal to 9.0.19. The imaging apparatus of claim 1, wherein the apparatus overdrives alight source of the illumination assembly during the illuminationperiod.
 20. The imaging apparatus of claim 3, wherein the apparatusoverdrives a light source of the illumination assembly during theillumination period.